摘要:

This study was designed to demonstrate that Gas Chromatography–Atomic Emission Detection (GC-AED) can be used to set in a Compound-independent calibration (CIC) for quantifying organic compounds with various chemical functions using one reference compound. Experiments were carried out with thirteen organic molecules containing twelve atoms of carbon and different amount of hydrogen, oxygen or sulphur.

ISSN:0003-2719    

DOI:10.1080/00032719908542921

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

A simple and selective photometric procedure was developed for the micro-determination of periodate in aqueous media. The method is based on the reaction of periodate with Gallocyanine at pH = 4.8. The reaction was monitored photometrically by measuring the absorbance of the reaction mixture at 620 nm. The effects of reagent concentration, temperature and influence of other species for the determinations of periodate were investigated. Periodate can be determined in the range of 0.02-2.20 μg/ml, with a relative standard deviation of 1.96% for ten replicate measurements of 0.13 μg/ml periodate. Periodate can be determined in the presence of iodate or iodide.

ISSN:0003-2719    

DOI:10.1080/00032719908542922

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

Principal component analysis and classification techniques were used to investigate the effect on the properties of wine of different fungicide treatments performed on the grapes. 55 variables were determined, 17 on the grape just-collected and the others on the wines. 27 samples of grape and wine were considered, produced in 1992, 1993" acceptdate="and 1994. The wines were classified as a function of the production year but no important correlation was found between fungicide treatment and the wine features. The classification was performed by a SIMCA method.

ISSN:0003-2719    

DOI:10.1080/00032719908542923

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

A novel sol-gel method is applied for the preparation of solid-phase microextraction (SPME) fibers. Scanning electron microscopy experiments suggested a porous structure for the poly(dimethylsiloxane) (PDMS) coating. SPME-GC analysis provided evidence that the sol-gel fibers have some advantages, such as high thermal stability, efficient extraction rates, high velocities of mass transfer, and spacious range of application.

ISSN:0003-2719    

DOI:10.1080/00032719908542924

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

Gas chromatography (GC) was used in the analysis of the synthesized oligomeric mixtures, involving poly(ethylene glycol)s, poly(ethylene oxide) monomethyl ethers, poly(ethylene oxide) dimethyl ethers and crown ethers. It was demonstrated that the samples could be successfully analyzed on the wide bore capillary column with cross-linked polar stationary phase (FFAP) without derivatization. An on-column injection technique is used to avoid possible sample distortion. Identification and quantitative analysis were achieved taking advantage of the GC homologues retention rule and the FID effective carbon number response rule, thus the limitations of some standard availability and purity problems were avoided. Much useful information such as average molecular weight, polydisperse distribution and so on were obtained by the established method, which is very important in the process monitoring and product quality control.

ISSN:0003-2719    

DOI:10.1080/00032719908542925

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor